Scientists use scanning probe microscopes (SPMs) to reveal data about various properties of materials, such as gold or silicon, at very fine resolution, down to molecules and atoms of the materials. SPM's are a family of high magnification instruments that may include Scanning Tunneling Microscopes (STMs), Atomic Force Microscopes (AFMs), Near Field Scanning Optical Microscopes (NSOMs), among others.
SPMs typically include piezoelectric motors that move physical probes with sufficient precision to provide ultra-high resolution on the nanometer scale and below. Piezoelectric motors and actuators provide fine positioning and optionally vibrational excitation to one or more probe tips. SPM probes are of varying shapes made from both conducting and nonconducting materials all of which share the characteristic of tips that can interact mechanically and electromagnetically with atoms and surfaces with tens of picometer (10-12 m) physical precision and spatial resolution.
Current SPMs typically require many channels of sophisticated analog and digital electronic circuitry or instrumentation to deliver electrical excitations to motors, probes, surfaces and other SPM components and receive responses produced by these SPM components. These signal channels and others delivered from external electrical, optical, thermal, magnetic, chemical and mechanical components require computer based data acquisition systems. Further, the multiple channels excitation, response and control typically must be synchronized, and sometimes analyzed, in real time.
Areas of application of SPMs are expanding rapidly. New areas of materials analysis include sequencing of single strands of DNA and investigations of transport in living cells. New advanced nanomaterials are being synthesized using SPMs equipped with nanometer scale chemical deposition equipment with the target of producing thousands of nanometer scale components in a short period of time. Thus, the current SPM control systems in use today could benefit from improved operation to help meet the needs of these new applications and their predicted growth in complexity.
Another area in which SPM control systems can be improved is in connection with their user interfaces. The current generation of SPM control systems can be configured and operated using software tools that provide a graphical user interface for designing experiments. This provides a conceptually simple interface to the control system for a user since they can graphically select and connect various hardware elements represented iconically rather than by scripting or other written programming. However, such iconic user interfaces are typically constrained because the available devices that can be used in the experiments are normally limited to pre-defined modes of operation programmed into the control system. For example, a SPM control system having an FPGA will be programmed with a number of available devices that can be used in different experiment setups; however, the existing software tools used to define the experiment will generally only have certain pre-defined modes or functions for using those devices, and to add additional modes, new programming of the FPGA controller is written and compiled. This reduces the usability of the software tools since it requires interfacing with the system beyond the higher-level iconic user interface. Thus, current SPM control systems and software configuration tools used in these control systems could benefit by providing users with an iconic user interface that has increased flexibility in configuring and using the various hardware devices available in the control system. Other control systems for controlling equipment and instruments other than SPM can also benefit from these improvements which are described below.